Biomonitoring is one of the tools used to assess the mutagenic potential of the atmosphere. In this study, the mutagenicity of Tradescantia pallida, a species of plant largely present in urban environments, was investigated. The objectives of this study was to estimate the mutagenic potential of vehicular flow through the TRAD-MCN bioassay in cities located at different altitudes in the southwest mesoregion of Mato Grosso do Sul, Brazil, to infer possible abiotic agents that may contribute to the effects of atmospheric pollutants, and finally to map the cities with greater risks to the health of the local population. To achieve these objectives, the Tradescantia-micronucleus test was performed on young buds of T. pallida collected between August 2015 and August 2016 in nine cities of Mato Grosso do Sul. These buds were exposed to traffic flows of various intensities. The data collected consisted of measurements of meteorological parameters and vehicular traffic counts for each city. The variables considered were: mean ambient temperature; micronuclei frequency; vehicular flow; altitude; relative humidity; pluviosity. The application of the Trad-MCN bioassay, with the consideration of environmental variables and altitudes, and the use of the Kernel interpolation technique, allowed us to map the areas with significant pollution risks to the population. The highest frequency of exposure to mutagens occurred in the cities with the highest vehicular traffic intensity. The average ambient temperature failed to show a linear association with the frequency of the micronuclei in the samples analyzed (r = 0.11). A positive correlation was observed between micronuclei frequency and vehicular flow, (r = 0.67; p ≤ 0.001%) and between micronuclei frequency and altitude (r = 0.24; p ≤ 0.05). A negative correlation was found between relative humidity and micronuclei frequency (r = -0.19; p ≤ 0.05%). Thus, higher micronuclei frequency tended to be present in locations with low relative humidity and high altitudes and vehicular flow.
We tested the bioactivity of aqueous extracts of Ludwigia spp. (Myrtales: Onagraceae) on the biological cycle of Plutella xylostella. We assessed the duration of and viability during the larval, pupal and adult phases, as well as the influence of the extracts on the fecundity and hatching of P. xylostella eggs. Subsequently, we phytochemically screened the extracts. The extracts of L. tomentosa and L. longifolia reduced the pupal weight instead of prolonging the larval stage of P. xylostella. The L. tomentosa effect caused higher larval mortality and reduced the fecundity and hatching of P. xylostella eggs, and L. sericea reduced the egg survival. The phenolic compounds—flavonoids, condensed tannins and alkaloids—were more abundant in L. nervosa, L. tomentosa, L. sericea and L. longifolia. The L. tomentosa, L. longifolia and L. sericea extracts were bioactive, and these species showed the best results regarding their ability to control P. xylostella populations, because these plants produce substances able to inhibit food consumption and interfere with the morphological and physiological transformations of the offspring and the oviposition of adults.
The impact four cultivation systems on the soil fauna was studied, using Oribatida and Gamasida acarids as bioindicators and collembolan. The research was carried out in experimental fields, located in EMBRAPA - CPAO in Dourados, Centerwest of Brazil from July 1997 to December 1999. The constant pasture system presented smaller impact on the soil fauna followed by agricultural cattle rotation and a direct plantation system. In the conventional plantation series, the populational density of the mesofauna organisms was low, especially collembolan families.
O impacto de quatro sistemas de cultivo sobre a fauna de solo foram estudados, utilizando-se como bioindicadores os acari Oribatida e Gamasida e os Collembola. A pesquisa foi conduzida em campos experimentais, localizados na EMBRAPA - CPAO no município de Dourados, MS, no período de julho de 1997 à dezembro de 1999. O sistema de pastagem contínua apresentou menor impacto sobre a fauna de solo seguido da rotação agricultura pecuária e do sistema de plantio direto. Nas sucessões do plantio convencional, a densidade populacional dos organismos da mesofauna foi baixa, em especial as famílias de colembolos
The indiscriminate use of synthetic insecticides caused an increase in the resistance of Plutella xylostella (Linnaeus, 1758) (Lepidoptera: Plutellidae) to almost all classes of insecticides, as well as affected the environment and non-target organisms. Thus, the search for less harmful alternatives with the purpose of reducing the application of these insecticides has become a priority. A possible alternative to reduce the use of synthetic insecticides is by using botanical insecticides, given the thousands of existing compounds derived from secondary metabolism in plants. In this study, we tested the following hypotheses: (i) the aqueous and ethanolic extracts of native plants reduce the food consumption of larvae and oviposition of adults of P. xylostella; (ii) these botanical species can act as potential plant insecticides. The objective of this work was to evaluate the effect of plant extracts on the feeding preference of larvae and oviposition of adults of P. xylostella. For this, cabbage discs treated with aqueous and ethanolic extracts of Schinus terebinthifolius, Annona coriacea, Annona crassiflora and Serjania marginata were given to larvae. The concentrations used for the aqueous extracts were of 5 and 10 mg mL-1, and for the ethanolic extracts were of 1 and 5 mg mL-1. Both extracts of the four tested plant species showed oviposition suppressed. The extract of S. marginata showed the lowest rates of suppression. All treatments with ethanolic extracts showed a phagodeterrant effect being that the aqueous and ethanolic extracts of A. crassiflora and S. terebinthifolius were the most effective as antifeedants on third instar larvae by P. xylostella.
The present study aims to relate the micronucleus frequency in Tradescantia pallida to environmental factors and cardiorespiratory diseases to infer the effect of air pollution. The number of hospitalizations, diseases cases, frequency of micronuclei in plants, environmental variables, altitude, and vehicle traffic in cities of Mato Grosso do Sul were evaluated due to the high flow that surrounds agribusiness. The frequency of micronuclei decreased with the increase in relative humidity, while the altitude did not influence the mutagenicity or genotoxicity of the evaluated plants. The municipalities with micronucleus frequencies above 200 had the highest number of vehicle and cardiorespiratory diseases. Biomonitoring data obtained in cities throughout the year indicate that the number of cardiorespiratory diseases was probably due to vehicular pollution, which is evidenced by the increased frequency of micronuclei in T. pallida.
Abstract. The communication between leaf-cutting ants occurs through chemical interactions and sound, which are important processes in the complex social system of these organisms. Studies have focused on the characterization and importance of stridulation and vibration of the substrate for ants in general. However, for leaf-cutting ant species, little information is available about the characterization and the function of vibration of the substrate during preparation and incorporation of plant material into the symbiotic fungus by workers. Therefore, the objective of the present study was to describe the vibration in Eucalyptus leaves generated by the stridulation of Atta laevigata (Smith) workers during processing and incorporation of the plant material into the symbiotic fungus, and to discuss its possible function. Vibrational signals were recorded with a laser vibrometer. The amplitudes of the emitted signals varied according to the behaviors performed, that is, each behavior showed a characteristic amplitude. Thus, the vibration in the leaves probably can aid in the efficiency of these ants during the processing of the vegetal material for the incorporation in its symbiont.Vibração do substrato vegetal gerada pela estridulação de operárias durante o cultivo do fungo em Atta laevigata (Smith) (Hymenoptera: Formicidae)Resumo. A comunicação entre as formigas cortadeiras ocorre por meio da interação química e do som, processos importantes no complexo sistema social destes organismos. Existem vários estudos enfocando a caraterização e a importância da estridulação e vibração do substrato para as formigas em geral. Contudo, pouco se tem descrito para as espécies de formigas cortadeiras sobre a caracterização e função da vibração do substrato durante o preparo e a incorporação do material vegetal pelas operárias no fungo simbionte. Assim, o presente trabalho descreveu a vibração nas folhas de Eucalyptus sp. gerada pela estridulação das operárias de Atta laevigata (Smith) durante o processamento e incorporação destas folhas no fungo simbionte, além de interpretar sua possível função. Os sinais vibratórios foram gravados com um vibrômetro a laser. As amplitudes dos sinais emitidos variaram conforme os comportamentos executados, ou seja, cada comportamento apresentou uma amplitude característica. Desse modo, a vibração nas folhas provavelmente pode auxiliar na eficiência dessas formigas durante o processamento do material vegetal para a incorporação no seu simbionte.
A produção de mel tem alcançado bons resultados nos últimos anos, mas o país tem potencial para melhorar ainda mais esse desempenho. Portanto, há necessidade de investir cada vez mais em pesquisas nessa área. Objetivou-se com este trabalho promover, acompanhar e avaliar as transformações no Assentamento Areias, localizado no município de Nioaque, após a implantação da apicultura orgânica. Além disso, procurou-se explorar o potencial da área pantaneira, de forma sustentável, na criação de abelhas africanizadas Apis melífera, em Reserva Legal. Buscou-se desenvolver esta atividade de maneira coletiva, como uma proposta agroecológica de geração de renda alternativa e fonte alimentar, reunindo e compartilhando os saberes científicos adquiridos pelos docentes e discentes da Universidade Federal da Grande Dourados/UFGD, e as experiências acumuladas dos assentados com o sistema de produção familiar. O acompanhamento e o alcance dos objetivos estabelecidos foram verificados a cada 30 dias. Entrevistas individuais e reuniões participativas foram realizadas com o grupo de produtores do assentamento de Areias, com o objetivo de coletar dados quantitativos e qualitativos relacionados ao manejo das abelhas e geração de renda. Os resultados foram satisfatórios, pois a apicultura orgânica promoveu um impacto positivo no local, por meio do conhecimento de novas técnicas e aplicabilidade na criação das abelhas. Desta forma, este estudo trouxe subsídios e reflexões para as famílias do assentamento, técnicos, gestores, tomadores de decisão e a sociedade lidarem com a dualidade do sistema convencional de produtividade e o sistema de produção orgânica e agroecológico.
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